Semiconductor dice must be tested during the manufacturing process to insure the reliability and performance characteristics of the integrated circuits on the dice. Accordingly, different testing procedures have been developed by semiconductor manufacturers for testing semiconductor dice. Standard tests for gross functionality are typically performed by probe testing the dice at the wafer level. Probe testing at the wafer level can also be used to rate the speed grades of the dice. Burn-in testing is typically performed after the dice have been packaged. During burn-in testing the packaged dice are subjected to elevated temperatures for extended periods of time while different electrical parameters of the integrated circuits are evaluated.
In addition to conventional plastic or ceramic semiconductor packages, semiconductor dice are also made in an unpackaged or bare form. A known good die (KGD) is a bare die that has been tested to insure a quality and reliability equal to a conventionally packaged product. For testing bare semiconductor dice, semiconductor manufacturers have developed specialized testing apparatus, such as carriers adapted to retain a single bare die for burn-in and other test procedures.
Bare dice that do not pass a test procedure are typically discarded by the manufacturer. Discarding defective dice decreases the yield of the known good die manufacturing process and adds to the expense of the dice. It would be advantageous to provide a test repair procedure that also increases the yield in the manufacture of known good dice.